Not to put too fine a point on Jessica Johnson's otherwise worthwhile
posting, Rohm & Haas's current formulation of the plastic known as B-72
is not what it was a few years ago.  What the differences are, exactly,
we do not know; trade secrets, you see.  Nothing personal of course; just
business as usual.
 
These are only a couple (I have old and new samples of B-72) of the
materials which I am in the process of testing.
 
This testing is not supported by any local, state, or federal organization.
 
It may not be cost effective, but then I don't have to answer to anyone,
justify a budget, or write a final report.
 
I only have to convince myself that what I am doing is in the best
interests of the artifact at hand.  I'll leave it to others to interpret
the artifact and place it in context.
 
Jack C. Thompson
Thompson Conservation Laboratory
Portland, OR
 
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